Cut the eggplant and zucchini into small cubes.
Sprinkle the eggplant cubes with salt and let them sit in a colander for 30 minutes.
Rinse and drain the cubes afterward.
Finely chop the onion.
Drain the sun-dried tomatoes (reserve 4 tablespoons of the oil).
Cut the bell peppers into half strips.
Mix the tomato juice with the broth.
Heat the reserved tomato oil in a large skillet and sauté the onion until soft and translucent (but not brown).
Squeeze the garlic clove into the skillet, then add the eggplant, zucchini, sun-dried tomatoes, bell peppers, and oregano.
Cook while stirring for about 3 minutes.
Add the rice to the skillet.
Stir well and cook, stirring constantly until the rice grains become translucent.
Pour in 100ml of the tomato broth mixture and stir the rice.
Let the rice simmer over medium-low heat in an open pan until most of the liquid is absorbed.
Gradually add the remaining broth mixture, waiting until the previous amount is almost absorbed before adding more.
Stir regularly.
The risotto is done when the rice grains are al dente.
Stir in the grated cheeses until melted.
Continue heating until the cheese is fully melted.
Season the risotto with salt and pepper to taste.